Induction coil



1,641,364 Sept. 5, 1927" c. E. WHLSON INDUCTION COIL Filed April 17, 1925 Patented Sept. 6, 1927.

more!) STATES cnanrns E. WILSON, or ammnson, INDIANA, assrenon, BY un'snn nssrenmnn'rs,

, 1,641,364 PATENT OFFICE.

T ,IDELOO-BEMY CORPORATION, 01' DAYTON, OHIO, A CORPORATION OF DELAWARE.

v INDUCTION Application filed April 17, 1985. Serial No. 23,808.

pieces as has been the ractice heretofore.

Further objects an' advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherema preferred form of embodiment, of the present invention is clearly shown.

In the drawings: I

Figs. 1 and 2 are plan and end Views res ectively of the material. used to provide the external portion of the magnetic circuit of an induction coil.

Fig. 3 is a sectional view of a coil including the present invention. The induction coil to which the present invention can be applied comprises a metal case 20 which contains a central core 21 consisting of a bundle of wires resting upon a porcelain base 22 supported by the bottom of the container 20. The core 21 is surrounded by a non-conducting tube 23, a secondary coil 24 and, a primary coil 25. The. cover of the container 20 comprises a metal piece 26 which supports a non-conducting bod 27 and terminals 28 and 29. The body 2; carries a hi h tension cable receiving spcket 30 attache by a conductor 31 to one end of the secondary coil 24. The other end of the secondary coil 24 and one end. of the primary are connected by wire 32 with terminal 28 and the other end of the primary 25 is connected by wire 33 with the terminal 29.

The external portion ofthe magnetic circuit which constitutes an embodiment of the present invention is indicated in Fig. 3 by a tube 40 comprising a plurality of layers formed by rolling up a strip of material including separate narrow strips of iron. This material is formed by pasting or gluing a strip of paper or other flexible nonconducting and non-magnetizable material 41 to a strip of soft iron suitable for inducjmaterial to a strip of tion coil work. The paperstrip. 41 is wider than the metal strip42 and both side edges of the paper project beyond the side edges of the metal strip. After the paste or glue has dried, the assembled strip of paper and iron is slit as indicated by the lines 43. The slits are parallel and extend beyond the .side edges of the iron stri but terminate within the mar ins of t e paper strip. The paper shoul be sufiiciently tough and strong to resist tearing after -the slits have been made and sufiiciently flexibleto permit rolling the assembled material into a tube such as is indicated at 40.

The advanta es of the present invention are apparent w en it is considered that but two pleces of metal are handled in the formation of the external portion of the magnetic circuit for the induction coil. Heretofore it has been the practiceto assemble between the wall of the container and the coil windings a large number of pieces of'iron wire or narrow strips of iron in order to provide a magnetic circuit in which eddy current losses would be reduced to the minimum. By means of the present invention the cost of making .coils of this 7 type has been materially reduced on account of the reduction of time and labor in the formation of. the external portion of the magnetic circuit of the coil. As the paper strip is relatively thin, and the metal str ps are arranged regularly upon the paper, a large number of metal strips can be assembled within the space provided in the container for the magnetic circuit. a

While the form of embodiment of the invention as herein disclosed, constitutes apreferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What I claim is as follows:

1. The method of makingmaterial for a tubular magnetic circuit-of induction apparatus which com rises attaching a strip of flexible non-conductin nonmagnetizable exible magnetizable metal which is located within the side margins of the other strip, and in shearing the strips entirely across the metal strip but not. entirely across the other strip to provide a plurality of separate strips of metal assembled by the side margins of the nonconducting nonmagnetizable strip.

2. Material for the magnetic circuit of ininduction apparatus consisting (of a, plumb ity of separate strips 015 magnetizable metal secured f0 :1 strip of flexible nommagnetic 10 material in. proper, spaceci relation, the edges of said material extending beyond the respective edges of the metal strips.

In testimony whereof I lwreto affix my signature CHARLES E WILSON. 

